What is the definition of fog in meteorological terms?

Fog is defined in meteorological terms as a cloud with a base at or near the ground. This phenomenon occurs when water vapor condenses into tiny water droplets suspended in the air, reducing visibility. The formation of fog typically happens when the air becomes sufficiently cooled, allowing humidity to reach a saturation point, leading to the condensation of water vapor into small droplets. This definition emphasizes the unique relationship between fog and clouds, as both consist of condensed water but differ in their altitude, with fog forming at ground level.

The other options do not accurately capture the essence of what fog is. Strong winds that carry precipitation refer to weather patterns, not the definition of fog itself. A type of atmospheric front describes boundaries between air masses but does not define fog. Similarly, while fog can be associated with particular weather conditions, it is not categorized as a form of precipitation, which typically includes rain, snow, sleet, or hail. Therefore, the correct understanding of fog is its classification as a low-lying cloud that impacts visibility.